In the field of semiconductor chips and power modules, there are used power semiconductor devices such as a multi-pin IGBT (Insulated Gate Bipolar Transistor) having electrodes called a gate (G), a source (S) and a drain (D) on front and back sides of the semiconductor chip, and a 2-pin diode having a rectification function and having electrodes on front and back sides thereof.
A TO (Transistor Outline) and an SIP (Single Inline Package), in which power semiconductor chips such as IGBTs are packaged, diodes, and power modules, in which these semiconductor chips are sealed, are applied to many products, for instance, DC-DC converters for consumer equipment, inverters for vehicles and air conditioners, transportation means such as electric trains and bullet trains, and electric power transmission/distribution. The range of applications and the market size are increasing.
In general, an insertion-type power transistor such as a TO or SIP, which has been marketed, is a package which is configured such that a semiconductor chip is mounted on a lead frame, wire bonding is performed from electrodes on the chip surface to other lead frames, and the chip is resin-sealed. In addition, in a power module, a plurality of IGBTs and diodes are COB (Chip On Board) mounted, and after wire bonding, the IGBTs and diodes are sealed with a gel sealing material for insulation and protection. In general, in the power module with this structure, a mount board (a wiring pattern is formed of a metallic material such as Cu on a ceramic board) is disposed in the housing. IGBT chips and diode chips are connected by die-mounting to predetermined pattern locations on the mount board by using a bonding material such as solder, and wiring connections are made by wire bonding of, typically, Al.